In my German open application (Offenlegungsschrift) No. 2,554,132, published 16 June 1977, I have disclosed a device of this type in which a spray nozzle trained upon a stretched yarn, advancing continuously at high speed, is supplied with liquid dyestuff through two cascaded valves which are opened and closed at staggered intervals to emit short spurts of the dyestuff. A drawback of this device is the relative complexity of its valve-control system.
Another system, described in German open application (Offenlegungsschrift) No. 2,320,215 published 7 Nov. 1974, teaches the use of transversely shiftable nozzle carriers for a similar purpose. Such an arrangement facilitates color changes but only at a relatively slow rate.
A method known as Eastern Color Yarn-Dyeing Process, described for example in the German publication Farberei/Druckerei/Ausrustung, Vol. 3/1975, p. 237, utilizes a dyestuff jet trained upon a rotating disk whose frustoconical periphery scatters the impinging liquid into droplets reflected onto the yarn moving past. Such a system does not enable the production of reproducible coloration patterns and uses considerable amounts of colorant.